Yacon leaves amelliorate TGF-beta1/smad signaling in diabetic kidney

HONORÉ S. M.; GENTA S. B.; SANCHEZ S. S.

Potrero de los Funes, San Luis

Congreso; XLVII Reunión Anual de la Sociedad Argentina de Investigación en Bioquimica y Biologia Molecular; 2011

SAIB

Nephropathy is a common cause of morbidity and mortality in diabetic patients. Prevention of this complication is clearly required. Smallanthus sonchifolius (yacon) leaves containing mainly polyphenolic acids and the lactone enhydrin have been shown to ameliorate hyperglycemia in streptozotocin-induced diabetic rats. In the present study, we examined the beneficial effects of yacon leaves decoction in diabetic kidney and explored the possible underlying mechanism. Diabetic rats were orally administered with 10% yacon leaves water decoction (140mg dry extract/kg b.w.) for 30 days. Biochemical parameters in blood and urine, immunohistochemistry, western immunoblotting and qRT-PCR analysis were developed. Yacon decoction significantly decreased high blood glucose level in diabetic rats and improved insulin production. Diabeticdependent alterations in urinary albumin excretion, creatinine clearance, kidney hypertrophy and basement membrane thickening were attenuated by yacon decoction. These findings were associated with a marked decrease in TGFbeta1, TGFRII and p-Smad2/3. The expression of extracelullar matrix proteins as collagen IV, laminin-1, fibronectin and collagen III were also diminished in the yacon-treated group. These results suggest that yacon leaves is a protective agent against renal damage in diabetic nephropathy, whose action can be mediated by TGFbeta/Smads signals.